Diagnostic Mode

You access the diagnostic mode by first resetting the iPod. When
you see the Apple logo, press and hold Previous and the Select button
until you see a reversed Apple logo. Let go and you'll see the
following entries.

5 In 1

Performs a series of tests including checking the backlight,
memory, and USB ports.

RESET

resets the iPod. This is one way to exit the Diagnostic screen.

KEY

you press the keys, it tells you if they work.

CHGRCUR

I'm guessing on this one. Seems to allow you to turn on and off charging methods.

REMOTE

Allows you to test the buttons on the remote control.

HP STAT

Indicates if something is plugged into the headphone jack and the
state of the hold switch.

SLEEP

Puts the iPod to sleep.

BATT A2D

Checks the iPod's power supply and (maybe?) indicates the amount
of charge in the battery.

A2D STAT

Battery and power supply related.

FIREWIRE

Checks FireWire chip.

HARD R/W

Read and write hard drive test. Reads HDD pass if all goes well.

SMRT DAT

Another hard drive test. Reads RETRACTS 4 REALLOCS 0 PENDING 0.

SMRT SCAN

Appears to be akin to a regular iPod's Disk Scan test. This takes
several minutes so don't perform this test unless the iPod is plugged
into a power source.

DRV TEMP

Displays drive temperature.

DISKMODE

Throws the iPod into Disk Mode.

WHEEL

Run your thumb around the wheel and watch the values change.

CONTRAST

Runs contrast test. My Diagnostic screen was really light. Running
this test made it much darker and more legible. Proceed through the
screens by pressing the Play button.

AUDIO

Displays audio gain. Can move up as high as 127 by pressing
Forward button. Default is 120.

STATUS

tells you what's plugged into your iPod -- whether it's being
charged via FireWire and has something plugged into the headphone
port, for example.

IRAM3

unknown

CLEAR BLKS

unknown

ALLSDRAM

unknown

HDD DROP

unknown

To move from test to test, use the Previous and Forward buttons. To
initiate a test, press the Select button. To exit tests when they're
completed, press the Play button.

Shuffle Lights

Main

Solid orange

Charging, OK to disconnect.

Blinking orange

Mounted, do not disconnect.

Solid green

Connected to charger: fully charged, OK to disconnect.Not connected: play. Light will turn off after two seconds.

Blinking green

Paused: light will turn off after one minute.

Solid orange when you press a button

Hold is on. To turn it off, hold the Play/Pause button
for three seconds.

Solid green when you press a button

Normal operation of that button. The light stays on as long as
you press the button.